If you are collecting 1/5th of the spoils and the most beautiful captured women as slaves which Muhammad did people might suspect that you are not preaching for God but rather for yourself. They might suspect that you are a conman. It is essential that you convince them that you have the purest of motives. What better way than to command them to be good. Command them to pay a poor tax. (I don't know if Muhammad took a cut of this poor tax or not. I know that in modern times a lot of so called charity money funds Jihad.) Commanding people to be good is perhaps the most effective way to get people to believe that you are a prophet.
[17.23] And your Lord has commanded
that you shall not serve (any) but Him, and goodness to your parents. If either
or both of them reach old age with you, say not to them (so much as) "Ugh" nor
chide them, and speak to them a generous word.
[17.24] And make yourself submissively gentle to them with compassion, and say: O my Lord! have compassion on them, as they brought me up (when I was) little.
[17.25] Your Lord knows best what is in your minds; if you are good, then He is surely Forgiving to those who turn (to Him) frequently.
[17.26] And give to the near of kin his due and (to) the needy and the wayfarer, and do not squander wastefully.
[17.27] Surely the squanderers are the fellows of the Shaitans and the Shaitan is ever ungrateful to his Lord.
[17.28] And if you turn away from them to seek mercy from your Lord, which you hope for, speak to them a gentle word.
[17.29] And do not make your hand to be shackled to your neck nor stretch it forth to the utmost (limit) of its stretching forth, lest you should (afterwards) sit down blamed, stripped off.
[17.30] Surely your Lord makes plentiful the means of subsistence for whom He pleases and He straitens (them); surely He is ever Aware of, Seeing, His servants.
[17.31] And do not kill your children for fear of poverty; We give them sustenance and yourselves (too); surely to kill them is a great wrong.
[17.32] And go not nigh to fornication; surely it is an indecency and an evil way.
[17.33] And do not kill any one whom Allah has forbidden, except for a just cause, and whoever is slain unjustly, We have indeed given to his heir authority, so let him not exceed the just limits in slaying; surely he is aided.
[17.34] And draw not near to the property of the orphan except in a goodly way till he attains his maturity and fulfill the promise; surely (every) promise shall be questioned about.
[17.35] And give full measure when you measure out, and weigh with a true balance; this is fair and better in the end.
[17.36] And follow not that of which you have not the knowledge; surely the hearing and the sight and the heart, all of these, shall be questioned about that.
[17.37] And do not go about in the land exultingly, for you cannot cut through the earth nor reach the mountains in height.
[17.38] All this-- the evil of it-- is hateful in the sight of your Lord.
[20.112] And whoever does good works and he is a believer, he shall have no fear of injustice nor of the withholding of his due.
24.2] (As for)
the fornicatress and the fornicator, flog each of them, (giving) a hundred
stripes, and let not pity for them detain you in the matter of obedience to
Allah, if you believe in Allah and the last day, and let a party of believers
witness their chastisement.
[24.3] The fornicator shall not marry any but a fornicatress or idolatress, and (as for) the fornicatress, none shall marry her but a fornicator or an idolater; and it is forbidden to the believers. (Notice that Muhammad did a lot of fornicating Notice line 32 in the same chapter which follows)
[24.32] And marry those among you who are single and those who are fit among your male slaves and your female slaves; if they are needy, Allah will make them free from want out of His grace; and Allah is Ample-giving, Knowing. (What’s this about marrying male slaves?)
[24.33]…do not compel your slave girls to prostitution