Charles Ellicott Commentary Mark 13:28

"Now from the fig tree learn her parable: when her branch is now become tender, and putteth forth its leaves, ye know that the summer is nigh;" — Mark 13:28 (ASV)

You know that summer is near.—Many of the best manuscripts give “it is known,” but it may fairly be assumed, from the parallel passages in Saint Matthew and Saint Luke, that this was the error of an early transcriber of the document which served as a basis for the reports of all the three Evangelists.