al-Birr is interpreted in three ways:
1. By al-Birr, maintaining kinship ties (ṣila / observing the bonds of kinship) is meant; as in the following verses:
Do not make Allah an obstacle to your oaths, so as to prevent you from birr {that is, maintaining the bonds of kinship}... (al-Baqara 2:224)
Allah does not forbid you from birr towards those who have not fought you because of religion nor driven you out of your homes {that is, maintaining the bonds of kinship with such people}... (al-Mumtaḥana 60:8)
2. al-Birr is used in the sense of obedience, as in the following verses:
Cooperate in birr {that is, abandoning disobedience [obedience]} and taqwa (God-consciousness)! (al-Māʾida 5:2)
There is a similar command in the same surah.
{Yahya} was barr {that is, one who abandons disobedience [obedient]} to his parents. (Maryam 19:14)
There is another similar instance in the same surah, that is, he is obedient to his parents.
He made me barr {that is, obedient} to my mother Maryam. (Maryam 19:32)
Speak concerning birr {that is, obedience} and taqwa! (al-Mujādila 58:9)
Indeed, the record of the abrar (plural of birr) {that is, the obedient ones} is in ʿIlliyyīn. (al-Muṭaffifīn 83:18)
3. al-Birr is used in the sense of taqwa (God-consciousness), as in the following verses:
You will never attain birr {that is, you will not attain the perfection of taqwa until you spend from that which you love in charity [zakāt]}. (Āl ʿImrān 3:92)
Turning your faces towards the east or the west is not birr {that is, not taqwa}. {Similarly, doing other such acts is not birr/taqwa}. Rather, birr {that is, taqwa} is of the one who believes in Allah... (al-Baqara 2:177)
Do you order people to birr {that is, obedience to Allah by following the Prophet Muhammad} and forget yourselves? (al-Baqara 2:44)