Hadith in Tirmidhi regarding mosquito and sip of water?

Can someone explain what this hadith means: > عن سهل بن سعد، قال قال رسول الله صلى الله عليه وسلم ‏ "‏ لو كانت الدنيا تعدل عند الله جناح بعوضة ما سقى كافرا منها شربة ماء > >Sahl bin Sa'd narrated that the Messenger of Allah (s.a.w) said: "If the world to Allah was equal to a mosquito's wing, then He would not allow the disbeliever to have a sip of water from it." > > — [Jami at-Tirmidhi](https://sunnah.com/tirmidhi:2320)