Declension table of ?śāsta

Masculine	Singular	Dual	Plural
Nominative	śāstaḥ	śāstau	śāstāḥ
Vocative	śāsta	śāstau	śāstāḥ
Accusative	śāstam	śāstau	śāstān
Instrumental	śāstena	śāstābhyām	śāstaiḥ śāstebhiḥ
Dative	śāstāya	śāstābhyām	śāstebhyaḥ
Ablative	śāstāt	śāstābhyām	śāstebhyaḥ
Genitive	śāstasya	śāstayoḥ	śāstānām
Locative	śāste	śāstayoḥ	śāsteṣu

Compound śāsta -

Adverb -śāstam -śāstāt