Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(As for those who believe in Allah) as well as in Muhammad and the Qur'an, (and hold fast unto Him) and hold fast to believing in Allah's divine Oneness, (them He will cause to enter into His mercy) in Paradise (and grace) and they shall also receive His honour, (and will guide them unto Him by a straight road) He will confirm them on a straight path in this world. He says: He will confirm them in this world in faith and will enter them into Paradise in the Hereafter.
As for those who have faith in God and hold fast to Him, He will make them enter into mercy from Him, and bounty, and He will guide them to Him on a straight path.
From the servant come faith and holding fast by way of servanthood, and from the Exalted Lord bounty and mercy in the attribute of loving kindness. Then He says, “He will guide them to Him on a straight path.” He will give them the guidance and rectitude to know that the recompense they find and the generosity they see come from God's bounty and mercy, not from their faith and holding fast. As the Prophet said, “There is none of you who will be saved by his deeds.”
They said, “Not even you, O Messenger of God?”
He said, “Not even I-unless God envelops me with His mercy.”
As for those who believe, in the affirmation of the Oneness of essence and hold fast to it in light of the multiplicity of the attributes and their separations, and [who] are mindful of the union at the level of differentiation, He will surely admit them to mercy, from the gardens of the attributs, the quintessence of which cannot be known, and bounty, from the gardens of the Essence, and He will guide them to Him by a straight path, by remaining upright in maintaining the unity in light of the differentiations of multiplicity. Alternatively, [it means] a mercy from the gardens of the acts, bounty from the gardens of the attributes, and that He will guide them to Him by a straight path by way of the differentiations of the attributes towards the annihilation in the Essence. The former [interpretation] fits better in this instance. It is for you to effect a [similar] correspondence between the differentiations of your existence and the states of your soul wherever possible in this sūra on the basis of the rules that have already been mentioned in [the sūra of] Āl ʿImrān [Q. 3], and God, exalted be He, knows best.
(So, as for those who believed in Allah and held fast to depend on Him,) by worshipping Him and relying on Him for each and every thing. Ibn Jurayj said that this part of the Ayah means, "They believe in Allah and hold fast to the Qur'an.''
فَسَيُدْخِلُهُمْ فِى رَحْمَةٍ مَّنْهُ وَفَضْلٍ
(He will admit them to His mercy and grace,) meaning, He will grant them His mercy and admit them into Paradise, and will increase and multiply their rewards and their ranks, as a favor and bounty from Him.
وَيَهْدِيهِمْ إِلَيْهِ صِرَطاً مُّسْتَقِيماً
(and guide them to Himself by a straight path.) and a clear way that has no wickedness in it or deviation. This, indeed, is the description of the believers in this life and the Hereafter, as they are on the straight and safe path in matters of action and creed. In the Hereafter, they are on the straight path of Allah that leads to the gardens of Paradise.
As for those who believe in God and hold fast to Him He will surely admit them to mercy from Him and bounty and He will guide them to Him by a straight path. He will surely admit them sayudkhiluhum to mercy from Him: the particle indicating the future the letter sīn indicates that He will preserve their faith for them at the time of their deaths just as He has honored them with deeper knowledge and faith in the here and now. and He will guide them to Him by a straight path. This guidance is His honoring them [as they] came to know that this guidance is a bounty from God for them not because they deserve it and not because of their seeking effort toil or pains.