I think I somewhere read that the Buddha said that when you meditate (on breath) for 30 minutes in the morning and in the evening, you will be accompanied by happiness and peace throughout the day. Is that true and if yes, can you tell me the sutra? Thank you!
There are three considerations: getting into meditation, establishing connection with (whatever it's called), and maintaining connection.
First, to get into meditation you need to be careful not to scare yourself. If you start too rough on yourself you may end up secretly hating it. So all my teachers always said, start gentle and enjoy, little by little. Maybe 15 mins at a time, once a day. Then maybe 20.
Second, to establish connection with (I still don't know what it's called, but you'll know it once you get there), you need to have a good long meditation session. Maybe 90 minutes. Something like this. This is how long it takes to actually get deep. You don't need to have every meditation session be that long, only when you really feel like it. But it is important to do it a few times, until you catch the right feeling (state? mood?)
Then, once you have it, and feel it remain with you even in postmeditation, you need to maintain it. This typically takes about 30 mins twice a day. Or 45-60 mins once in the morning. Something like this.
These are my numbers. Everyone is different, so I'm sure a bunch of people here will have different opinions. But here it is anyway.
Better to think "what can I give", e.g. on good causes, than "what can I gain", e.g. optimice consuming (off). So the starter is: Better to Give than to Consume. In that way the effects are coming by it's own.
Duration, the ability to gain Jhana, depends on the sacrifies. The more and proper, incl. once past kamma, the longer, the more possible.
Generally one will not find an categorical answer to such a question in the suttas. "Just" lack of stinginess and freedom of remorse, as needed prerequisites for concentration are often mentioned in the suttas.
So generosity and virtue (moral & duties) are the prerequisites, the causes for gain the next step.
If "meditating" without the prerequisites, it will be neither Jhana, nor for the benefit in this, the next world and for a beyound. Just as even the riches would waste his merits continuously when just enjoying them off by dwelling in various kinds of sensuality (of which common usual meditation, consumend by many actually is) task and duties, as well causes for future and required fruits undone.
If one has done his tasks and duties, according to his/her needs/wants, relations one nurishes on, then, being free, gains the joy of remorse. This then, will lead to ease of which leads to concentration and to release.
It's good, having done ones task, having served that and those worthy of being served, to seek from time to time seclusion. Of cause the lesser needs/wants one has, the more could one tend to seclusion. (See Piti Sutta: Rapture on when seclution is proper and good for householder)
'Householder, you have provided the community of monks with robes, alms food, lodgings, & medicinal requisites for the sick, but you shouldn't rest content with the thought, "We have provided the community of monks with robes, alms food, lodgings, & medicinal requisites for the sick." So you should train yourself, "Let's periodically enter & remain in seclusion & rapture." That's how you should train yourself.'
Working on the base, giving right causes for effects, is most importand. There is of course much faith nedded to stick more with just focus on causes and trust that results will come.
Dana - Sila - Bhavana, step by step. And doing all the steps till it's limits (e.g. perfect in ones circumstances/livelyhood) to be able to take the next step. Look for a good stand where you are, right now.
This Dhamma is not for "wellness" and trade, but for the escape from suffering and the welfare of many. It's not thought for compensation but for release.
May all of you become rightouse full time Yogies (one who takes on the task, worker; e.g. practicing the whole path) soon, maybe even renounce the world today, may you day by day, with all your deeps, develop the causes for this auspicious conditions.
(On the generouse request and suggestion of Nyom Lanka, some additions and links, for better understandig are added. There comes also a nice story, provided by the wanderer Isiul-Dhamma, a simile, into mind, describing the path of liberation: under kamma and the pāramīs, the prisoner story.)
A King asking a wise: mil 3.1.3
Now what do you think, O king? Is it when the battle is set in array against you that you set to work to have a moat dug, and a rampart put up, and a watch tower built, and a stronghold formed, and stores of food collected? Is it then that you would have yourself taught the management of elephants, or horsemanship, or the use of the chariot and the bow, or the art of fencing?'
'Certainly not, Sir.'
'Just so, great king, is effort concerned now with what still remains to be done, former effort has accomplished what it had to do. For it has been thus said, O king, by the Blessed One:
"Betimes let each wise man work out That which he sees to be his weal! Not with the carter's mode of thought, but firm p. 103 Let him, with resolution, step right out. As a carter who has left the smooth high road, And turned to byways rough, broods ill at ease 1-- (Like him who hazards all at dice, and fails)-- So the weak mind who still neglects the good, And follows after evil, grieves at heart, When fallen into the power of death, as he, The ruined gamester, in his hour of need 2."
[Note: This is a gift of Dhamma and not meant for commercial purpose or other low wordily gains by means of trade and exchange.]