COMMENTARY on 58:13
A. Yusuf Ali:

Translation:
Is it that you are afraid of spending sums 5352 in charity before your private consultation (with him)? If, then, you do not so, and Allah forgives you, then (at least) establish regular prayer; practise 5353 regular charity; and obey Allah and His Messenger. And Allah is well-acquainted with all that you do.
Commentary:

5352  Note the plural here, Sadaqat, instead of the singular, Sadaqah in verse 12 above. While people with the foibles described in n. 5350 may be willing to spend "something" (small) in charity for a special consultation occasionally, they may be frightened of spending large sums when their needs for consultation may be numerous. What is to be done then? Are they to be shut out altogether? No. They are asked to be punctilious in the discharge of their normal duties of at least normal regular prayers and regular charity, "if Allah forgives you", i.e., if Allah's Messenger relieves them of further special contributions such as those noted in verse 12. This condition, "if Allah forgives you", provides the safeguard against the abuse of the privilege. The messenger would know in each case what is best for the individual and for the community.

5353  Zakah, which I have translated "regular charity", was instituted about A.H. 2.

 

Muhammad Asad:

Translation:
Do you, perchance, fear lest [you may be sinning if] you cannot offer up anything in charity on the occasion of your consultation [with the Apostle]? But if you fail to do it [for lack of opportunity], and God turns unto you in His mercy, remain but con­stant in prayer and render [no more than] the purify­ing dues, 24 and [thus] pay heed unto God and His Apostle: for God is fully aware of all that you do.
Commentary:
24  I.e., the obligatory tax (zakah) which is meant to purify a believer’s possessions and income from the taint of selfishness: implying that one’s inability to do more by way of charity does not constitute a sin.