וְיֵ֞שׁ אֲשֶׁ֨ר יִהְיֶ֧ה הֶֽעָנָ֛ן יָמִ֥ים מִסְפָּ֖ר עַל־הַמִּשְׁכָּ֑ן עַל־פִּ֤י יְהוָה֙ יַחֲנ֔וּ וְעַל־פִּ֥י יְהוָ֖ה יִסָּֽעוּ׃
And sometimes the cloud was a few days upon the tabernacle; according to the commandment of the LORD they remained encamped, and according to the commandment of the LORD they journeyed.
Read halakhic rulings (Jewish law) on Numbers 9:20: and classical halakhic sources.