LSt.159:4 :ܨ݁ܦܚ ܠܠܝܐ ܐܝܟ ܥܘܢܕܢܐ ܠܟܠ ܫܪ̈ܒܬܐ‏ : for all peoples night falls suddenly, like death
See the entire entry for ṣpḥ vb. to occur suddenly