Abu Huraira reported Allah's Messenger (ﷺ) as saying:
A bulky person would be brought on the Day of judgment and he would not carry the weight to the eye of Allah equal even to that of a gnat. Nor shall We set up a balance for them on the Day of Resurrection" (xviii. 105). (ID)
Reference (ID): Sahih Muslim 2785 (ID)
In-book reference (ID): Book 52, Hadith 1 (ID)
USC-MSA web (English) reference(deprecated numbering scheme): Book 39, Hadith 6698 (ID)