Question: What is the maximum thawab given in return for good deeds and acts of worship?
ANSWER
The thawab for good deeds, sadaqah, and zakat is from tenfold to seven hundredfold and even more, as per one’s degree of ikhlas. The Qur’an al- karim says (what means):
(The likeness of those who spend their wealth in the way of Allah is as the likeness of a seed that sprouts into seven ears with a hundred grains in each ear. Allahu ta'ala gives even further to whomever He wills. He is wasi and aalim.) [Baqarah 261]

[Wasi means that He has power and might. The blessings He gives to humans does not cause Him poverty.

Aalim means that He knows everything with its conditions, reality, and essence. He knows the intention of, the degree of ikhlas, and the ability of infaq of those who perform infaq.

Infaq means spending and meeting needs.]

It is stated in hadith-i sharifs:

(For a good deed, thawab is given from tenfold to seven hundredfold. However, fasting is an exception. Allahu ta’ala says that He Himself gives the reward for it [without measure].) [Ibn Huzayma]

(Your Rabb is merciful. If a person intends to do a good deed but if he cannot do it, He records it for him as one thawab. If he does it, He records it for him from tenfold to seven hundredfold, or even more than this. If a person intends to do an evil deed but if he does not do it, He records it for him as one thawab. If he carries it out, He records it as one sin.) [Tabarani]

The mercy and blessings of Allahu ta'ala are abundant. In return for an iota of good deed, He gives as much thawab as a mountain. Everything belongs to Him. He gives whatever He wishes to whomever He wishes. No one can question Him.

Quantitative values attached to the amounts and numbers of
thawabs and sins, to celestial measures and distances, to time lengths in the hereafter, to the creation of the world, and to the
number of creatures are not intended for precision in the numbers and amounts, but for their greatness.