وَاعْبُدْ رَبَّكَ حَتَّىٰ يَأْتِيَكَ الْيَقِينُ

This concise but profound verse commands continuous worship of Allah until "certainty" (yaqin) comes. The "certainty" is interpreted as death - the moment when all doubts about the afterlife are removed and the reality of the next world becomes absolutely clear. This means worship should continue throughout one's entire life without interruption or retirement. The verse teaches that worship is not a temporary phase but a lifelong commitment, that spiritual obligations don't diminish with age or circumstances, and that consistency in worship is required until the very end of life. It emphasizes that there is no "retirement" from serving Allah, and that maintaining worship until death ensures one meets Allah in a state of obedience. This provides motivation for lifelong spiritual commitment and reminds believers that their relationship with Allah should remain active and vibrant throughout their entire existence.