瑜伽論記 13.100

13.100

述曰：習氣通二種，所謂現行及種子，此中約種子名習氣不約現行，故開二別，如何得知現行亦名習氣者，如阿羅漢齊足越坑名為習氣，此乃現行，故知通二種也。

The explanation states: Vāsanā applies to two kinds, namely active manifestations and seeds. Here, the term vāsanā is used in terms of seeds and not in terms of active manifestations; therefore, two distinct [objects] are opened. How is it known that active manifestations are also called vāsanā? Just as an arhat jumping over a ditch with feet together is called a vāsanā, this is an active manifestation, so we know it applies to both kinds.