Assalamualaikum dear Ustadh, may Allah grant you goodness upon goodness in this Dunya and the Akhira, Found some corn in a can outside a supermarket. Somebody had forgotten it, gave it to my in-laws. Is this haram or should I have left it there?

If it is something of little value that people do not bother to look for when they lose it, the scholars said there is no harm in taking it and you are not obliged to announce it. If it is something whose owner normally would come back searching for it, it is a lost item that is announced for a year, and once the owner is found, you return it to him.