四分律行事鈔資持記 3.85

3.85

云中。如是重重者，應云：不著祇支，不得著安陀會等。注云重著，亦觀時緣，非謂常爾。

In 'The Cloud says', 'layer upon layer like this' means one should say: without wearing the saṃkakṣikā, one must not wear the antarvāsa, and so forth. The note saying 'double wearing' also takes into account the circumstances of the time; it does not mean it is always like this.