一切經音義 2.86

2.86

瑟吒（二合下吒以上聲呼兩字合為下聲名二合）。

[Sanskrit syllable] ṣṭa (瑟吒: conjunct consonant; the second character 吒 is pronounced with the rising tone. Combining the two characters into the entering tone is called a conjunct consonant).