Rashi on Exodus 40:22/רש"י על שמות מ׳:כ״ב

1על ירך המשכן צפנה UPON THE SIDE OF THE DWELLING NORTHWARD — i. e. in the northern half of the width of the house (not by the northern wall) (Yoma 33b).

2ירך — This must be understood at the Targum renderd it: צדא. The real meaning is “thigh”, but the side of anything is just like the thigh which is at a person’s side.