With accent marks:
От добра́ добра́ не и́щут.
They do not seek good from good.
Few people know that this is only part of the proverb. Its full version sounds like this: "От овса кони не рыщут, а от добра добра не ищут" (Horses do not roam from oats, but they do not seek good from good). It means that if the horses are fed, they will not run away. If a person is doing well at home, he will not leave the family.
In its shorter version the proverb acquired a second meaning: when doing good to people, one should not expect the same from them. You need to do good selflessly.
Other Russian proverbs
Crowded, but not aggrieved.
The demon is not as scary as he is depicted.
Оne sees the mote in another's eye and ignores the log in his own.
You can't hide an awl in a bag.
Man does not live thanks to bread alone.
Another's soul is darkness.
There are no friends for taste and color.
If you like sledding, you should like to carry the sled.