Al-Baqarah: (110 - 112) And establish prayer and give...

Know that the Almighty commanded forgiveness and pardon concerning the Jews, and then followed it with His saying: {And [recall] when We took the covenant from the Children of Israel} (2:84), as a reminder that just as He obligated them regarding the welfare of others—to forgive and pardon—He also obligated them regarding their own welfare: establishing the obligatory prayers and giving Zakah (charity). By mentioning these two, He alluded to all other obligatory duties.

Then, He said afterward: {And whatever good you advance for yourselves}. The more apparent meaning here is voluntary acts of worship, such as supererogatory prayers and charities. The Almighty explained that they will find it ({you will find it with Allah}). This does not mean they will find the exact deeds themselves, because those deeds do not remain, nor is finding the essence of those things desirable. Therefore, what is meant is finding its reward and recompense.

Then He said: {Indeed, Allah, of what you do, is Seeing}. This means that nothing escapes His notice, whether little or much of their deeds. This serves as an encouragement, indicating that the Almighty rewards the small deed just as He rewards the large one, and as a warning against the opposite—evil deeds.

As for "good" (al-khayr), it is the pleasing benefit and what leads to it. Since the obedience a person performs leads them to great benefits, it must be described in this manner. In this same vein, the Almighty said: {And do good; perhaps you will succeed} (Al-Hajj: 77).

**{And they say, "None will enter Paradise except those who are Jews or Christians." Those are their [false] wishes. Say, "Produce your proof, if you are truthful." Rather, whoever submits his face to Allah while he is a doer of good, he will have his reward with his Lord, and no fear will come upon them, nor will they grieve.}* (2:111-112)