Is the "unity of purpose" intended to mean asceticism in this worldly life, or strength of focus and mental concentration?

The meaning of "gathering one's worries" (جمع الهم) is to direct the heart towards a single purpose, which is Allah Almighty and His pleasure, and to abandon all other preoccupations. This means that all worries become one single concern: contemplation of what benefits the servant in his return to Allah. Whoever does this, Allah will suffice him for all his other worries. The people of spiritual wayfaring have alluded to this meaning, and Ibn al-Qayyim explained it as gathering the heart's resolve upon Allah in love, repentance, and reliance, and gathering one's worries to execute His commands through دعوت (calling to Islam) and jihad. The proof for this is Allah's saying: "It is You we worship and You we ask for help."