What is meant by the servant's 'disposing of the universe' in the words of Ibn Taymiyyah, who describes reliance on God (tawakkul) and supplication (du'a) as means of attracting benefits and repelling harms?

This statement is from the Lord, blessed and exalted be He. The first two are worship and seeking aid, and the latter two are obedience and disobedience. Thus, turning to Allah means worshipping Him alone, and "acting" through His power means seeking His aid and relying upon Him, for there is no might nor power except with Allah. The servant's seeking aid from Allah Almighty and his truthful reliance on Him has an effect on facilitating matters and directing them according to the servant's desire. This does not mean that the servant has an independent power to direct affairs in the universe; rather, it means that Allah Almighty has made reliance upon Him a cause for the servant's strength and influence.