Vowels or tashkīl/7arakāt are the fat7a and kasra/khafd and damma combinations, you also have sukōn and shadda. Though what i will discuss is two meanings of صلوا: Sallō (pray) and Silō (uphold ties [of kinship]). In Arabic it consists of the same letters with different voweling:
وَصِلُوا الأَرْحَامَ، وَصَلُّو بِللَّيْل
(…Uphold the ties of kinship, and pray during the night…)*
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*Source: Sunan ibn Mājah, 3251, 4/319, chapters on food, darussalam.