‘Abdullāh ibn ‘Umar (may Allah be pleased with him) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) said: "Whoever buys food, let him not sell it until he receives it in full." Another wording reads: "until takes possession of it."
عن عبد الله بن عمر-رضي الله عنهما- عن النبي -صلى الله عليه وسلم- أنه قال: «من ابْتَاعَ طعاما فلا يَبِعْهُ حتى يَسْتَوْفِيَهُ»، وفي لفظ: «حتى يَقْبِضَهُ».
شرح الحديث :
Because taking possession of the food is something by which the contract is concluded and ownership is fully achieved, the Wise law-giver (Allah) has forbidden the buyer from selling it until he takes possession of it and receives it in full, i.e. becomes under his disposal.