ومن كلام له (عليه السلام) اقتص فيه ذكر ما كان منه بعد هجرة النبي (صلى الله عليه وآله) ثم لحاقه به
In this sermon Amīr al-mu’minīn has related his own condition after the Prophet's migration till his meeting with him. 
فَجَعَلْتُ أَتْبَعُ مَأْخَذَ رَسُولِ الله (صلى الله عليه وآله) فَأَطَأُ ذِكْرَهُ، حَتَّى انْتَهَيْتُ إِلَى الْعَرَجِ.
I began following the path adopted by the Prophet and treading on the lines of his remembrance till I reached al-‘Arj.
قال السيد الشريف رضي الله عته في حديث طويل: فقوله (عليه السلام): «فَأطَأُ ذِكْرَهُ»، من الكلام الذي رُمِيَ به إلى غايتي والفصاحة والايجاز، وأراد أني كنتُ أُعْطي خبره(عليه السلام) من بدء خروجي إلى أن انتهيتُ إلى هذا الموضع، وكنّى عن ذلك بهذه الكناية العجيبة.
As-Sayyid ar-Raḍī says: Amīr al-mu’minīn’s words “fa aṭa’u dhikrahu” constitute the highest forms of brevity and eloquence. He means to say that he was being given news about the Prophet from the commencement of his setting out till he reached this place, and he has expressed this sense in this wonderful expression.
 Since the commencement of prophethood, the Prophet remained in Mecca for thirteen years. For him, this period was of the severest oppression and destitution. The unbelievers of the Quraysh had closed all the doors of livelihood upon him, and had left no deficiency in inflicting hardships upon him, so much so that in order to take his life they began contriving how to do away with him. Forty of their nobles assembled in the hall of audience (Dār an-Nadwah) for consultation, and decided that one individual should be picked out from every tribe and they should jointly attack him. In this way, Banū Hāshim would not dare to face all the tribes, and the matter would quieten down on the payment of blood price. To give a practical shape to this scheme, these people sat in ambush near the house of the Prophet on the night of the first of Rabī‘ al-awwal, so that when the prophet slept in his bed he would be attacked. On this side the preparation for killing him was complete, and on the other side Allāh informed him of all the intrigues of the Quraysh unbelievers and commanded him to make ‘Alī (a.s.) sleep on his bed and himself to emigrate to Medina. The Prophet sent for ‘Alī (a.s.) and disclosing to him his plan, said: “‘Alī, you lie on my bed.” Amīr al-mu’minīn enquired: “O Messenger of Allāh, will your life be saved by my sleeping here?” The Prophet said: “Yes.” Hearing this Amīr al-mu’minīn performed a prostration in thanks-giving and, exposing himself fully to the danger, lay on the Prophet’s bed while the Prophet left from the rear door. The Quraysh unbelievers were peeping and getting ready for the attack but Abū Lahab said: “It is not proper to attack in the night because there are women and children also in the house. When morning dawns you attack him, but keep watch during night that he should not move anywhere.” Consequently, they kept their eyes on the bed throughout the night and soon, on the appearance of the dawn, proceeded forward stealthily. Hearing the sound of their footsteps, Amīr al-mu’minīn removed the covering from his face and stood up. The Quraysh gazed at him with stretched eyes as to whether it was an illusion or fact. After making sure that it was ‘Alī they enquired, “Where is Muḥammad?” and ‘Alī replied, “Did you entrust him to me, that now you are asking me?” They had no reply to this. Men ran to chase him but found footprints only up to the cave of Thawr. Beyond that there were neither footprints nor any sign of hiding in the cave. They came back bewildered while the Prophet after staying in the cave for three days left for Medina. Amīr al-mu’minīn passed these three days in Mecca, returned to the people their properties lying in trust with the Prophet and set off towards Medina to join the Prophet. Upto al-‘Arj which is a place between Mecca and Medina, he kept getting news about the Prophet and he continued his anxious march in his search till he met the Prophet at Qubā on the twelfth of Rabī‘ al-awwal, and entered Medina with him. (aṭ-Ṭabarī, at-Tafsīr, vol. 9, pp. 148—151; at-Tārīkh, vol. 1, pp. 1232–1234; Ibn Sa‘d, aṭ-Ṭabaqāt, vol. 1, Part 1, pp. 153–154; Ibn Hishām, as-Sīrah, vol. 2, pp. 124–128; Ibn al-Athīr, Usd al-ghābah, vol. 4, p.25; al-Kāmil, vol. 2, pp. 101–104; Ibn Kathīr, at-Tafsīr, vol. 2, pp. 302–303; at-Tārikh, vol. 3, pp. 180–181; Ibn Abi’l-Ḥadīd, vol. 13, pp. 303-306; as-Suyūṭī, ad-Durr al-manthūr, vol. 3, pp. 179-180; al-‘Allāmah al-Majlisī, Biḥār al-anwār, vol. 19, pp. 28-103).