瑜伽論記 17.342

17.342

下釋經中隨身念名，又隨逐身轉故者，起隨逐身境界而轉。彼所攝受故者，身念住是慧，為同時念助伴攝受方得作用，故復名念，是故彼得身念住名。

Below, it explains the term 'mindfulness accompanying the body' in the sutra. 'Furthermore, because it turns following along with the body' means that it arises and turns, following along with the objective realm of the body. 'Because it is gathered in by that' means that mindfulness of the body is wisdom; only when gathered in by simultaneous mindfulness as its companion does it attain its function; hence it is additionally called 'mindfulness', and therefore it attains the name 'mindfulness of the body'.