This is a sound clarification: performing what is commanded discharges the obligation. If it is accompanied by a sin of equal weight that undermines its purpose, that sin offsets the reward. If a person performs what is commanded incompletely, he is rewarded, but the obligation is not fully discharged: either the act must be repeated, its deficiency remedied, or he incurs sin.

Reflect, then, on this principle. What is commanded is like anything loved and sought: unless it is fully attained, the person commanded has not discharged his responsibility. Its deficiency must therefore be remedied by something of the same kind, by a substitute, or by repeating the entire act if its parts are interdependent. Otherwise, he remains liable, just as one does for committing what is prohibited.

The first case:
Someone pays less than the full amount of zakāh; he must pay the remainder.

The second:
Someone omits obligatory acts of Hajj; he remedies this by offering a sacrificial animal. The same applies to someone who omits obligatory elements of prayer whose omission can be remedied by prostration.

The third:
Someone offers a sacrificial animal with a defect, frees a slave with a defect, or prays without ritual purification.

The fourth:
Someone misses Friday prayer or jihad that is an individual obligation upon him.

If the commanded act is performed alongside something prohibited that conflicts with some of its constituent parts, it has not been fulfilled—as with intercourse while in ihrām, which invalidates it. If it does not conflict with any of its constituent parts, there will be