AphDiatess1990 6:10 :ܗܕܐ ܩܕܝܫܘܬܐ ܕܩܛܝܪܐ ܗܘܬ܂ ܟܕ ܐܦ ܨܒܝܢܗܘܢ ܡܫܘܬܦ ܗܘܐ ܩܕܝܫܘܬܐ ܕܝܢ ܕܢܛܪܘ܂ ܡܢ ܒܬܪ ܝܠܕܗ ܕܡܪܢ܂ ܕܚܐܪܘܬܗܘܢ ܗܘܬ‏ : this chastity was required even though their will (to behave so) was joint, but the chastity they kept after the birth of our Lord was of their free will
See the entire entry for qaddīšū, qaddīšūṯā n.f. sanctity