فَاِذَا فَرَغْتَ فَانۡصَبْ ۙ﴿۷﴾

So when you finish the prayer, strive in supplication.

Tafsir al-Qurtubi                                                                                                                         تفسیر القرطبی                                                    

قَالَ ابْنُ عَبَّاسٍ وَقَتَادَةُ: فَإِذَا فَرَغْتَ مِنْ صَلَاتِكَ فَانْصَبْ أَيْ بَالِغْ فِي الدُّعَاءِ وَسَلْهُ حَاجَتَكَ.

Sayyiduna Ibn ‘Abbas and Sayyiduna Qatadah – may Allah be pleased with them – said:  i.e. When you complete your Salah strive i.e. engage in supplication and ask Allah for your needs.

Tafsir Qurtubi (Al-Jame’ Li Ahkaam al-Quran) Imam Shamsuddin Muhammad ibn Ahmad al-Qurtubi t D. 671 A.H.