IshGen 100:20 :ܡܢܝܢܐ ܕܝܢ ܠܚܘܕ ܕܫܒܥܐ ܩ݁ܐܡ ܒܝܬܗ‏ : but the number seven alone is unique
See the entire entry for yāṯ, yāṯā n.m./f. essence