“feast.” The Hebrew word indicates that this would be a wonderful feast with food and wine.
“on the day Isaac was weaned.” Children were weaned late in the biblical world, sometimes at two, but sometimes as late as five. Infant mortality was high in biblical times, but if a baby lived long enough to be weaned, it had survived a very dangerous period of life, which was a cause for great celebration. For a wealthy man like Abraham, especially given that Isaac was a God-given miracle baby, this feast was a feast indeed. It may have even gone on for days.