Tafsir of Al-Isra 17:2

{ألا تتخذوا} (That you should not take): It is read with a ya (yattakhidhu) meaning: "Lest they take," and with a ta (tattakhidhu) meaning: "Do not take," similar to your saying: "I wrote to him that he should do such and such."

{وكيلا} (A guardian/disposer of affairs): A Lord to whom you entrust your affairs.

{ذرية من حملنا} (O descendants of those We carried): It is in the accusative case (nasb) as an instance of specification (ikhtisas). It is also said to be in the vocative case (nida') for those who read tattakhidhu with a ta as a prohibition. That is: We said to them, "Do not take a guardian besides Me, O descendants of those We carried..."

{مع نوح} (With Noah): It is possible that {وكيلا} and {ذرية من حملنا} are the two objects of tattakhidhu. That is: Do not take them as lords, similar to His saying: "Nor would he order you to take the angels and the prophets as lords." Among the descendants of those carried with Noah are Jesus and Ezra, peace be upon them.

It is read: {ذرية من حملنا} in the nominative case (raf') as a substitute for the waw in {تتخذوا}. Zayd ibn Thabit read it as dhirya with a kasra on the dhal. It is narrated from him that he interpreted it as "the children of children." God reminds them of the blessing in saving their forefathers from drowning.

{إنه كان عبدا شكورا} (Indeed, he was a grateful servant): It is said that when he ate, he would say: "Praise be to God who fed me; had He willed, He could have made me hungry." When he drank, he would say: "Praise be to God who gave me to drink; had He willed, He could have made me thirsty." When he clothed himself, he would say: "Praise be to God who clothed me; had He willed, He could have left me naked." When he put on sandals, he would say: "Praise be to God who shod me; had He willed, He could have left me barefoot." When he relieved himself, he would say: "Praise be to God who removed from me my harm in well-being; had He willed, He could have kept it within me." It is also narrated that when he intended to break his fast, he would offer his food to those who believed in him; if he found one in need, he would prefer them over himself.

If you ask: What is the relevance of "Indeed, he was a grateful servant" to what preceded it? I say: It is as if it were said: Do not take a guardian besides Me, and do not associate partners with Me, because Noah (peace be upon him) was a grateful servant, and you are the descendants of those who believed in him and were carried with him. So, take him as your model just as your forefathers took him as their model. It is also possible that it is a justification for their specification and the praise bestowed upon them, as they are the children of those carried with Noah; they are connected to him, and thus they deserved that specification. It is also permissible to say that it was mentioned by way of digression.