وَاعْبُدْ رَبَّكَ حَتَّىٰ يَأْتِيَكَ الْيَقِينُ
Vaa’bud raabbaka haattea ya’tiyakal yaakeen(yaakeenu).
And be a servant to Allah until what is certain (the last yakin is Hakk\ul (True) yakin until you reach the level at which one becomes a servant of Allah) comes to you.