You reminded me of the stabbing, and I had forgotten. ذَكَّرْتَنِي الطَّعْنَ وكُنْتُ نَاسِياً‏.‏

It is said that its origin is that a man charged at another man to kill him, and the one being attacked had a spear in his hand. Shock and panic caused him to forget what he had in his hand, so the attacker said to him, "Throw down the spear!" The other replied, "I have a spear, but I don't feel it!" "You reminded me of the stabbing"—the proverb—and he charged at his opponent and stabbed him until he killed him or defeated him. It is used to describe remembering something through something else. It is said that the attacker was Sakhr ibn Mu'awiyah al-Sulami, and the one being attacked was Yazin ibn al-Sa'iq. Al-Mufaddal said: The first to say it was Rahim ibn Hazn al-Hilali, who had moved with his family and possessions from his land to another. A group of people from the Banu Taghlib tribe intercepted him and recognized him, but he did not recognize them. They said to him, "Leave what you have." Wang said to them, "Here is the money, but do not harm the women." Some of them said to him, "If you want us to do that, then throw down your spear." He said, "And do I have a spear?" So he charged at them and began killing them one by one, reciting poetry and saying:
"Return to me the nearest of them, the farthest, for they have a guide with the sharp sword. You have reminded me of the thrust, and I had forgotten it."
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The proverb "You reminded me of the stabbing, and I had forgotten" is used when someone reminds another of something they had forgotten, and the person benefits from the reminder or recovers a forgotten ability, argument, or means.
Some of the closest English equivalents are:
"That reminds me."
Meaning: This reminded me.
This is the closest direct equivalent to the meaning of remembering because of something else.
"You just gave me an idea."
Meaning: You just gave me an idea.
This is used when someone's words cause one to remember something useful.
"Thanks for the reminder."
Meaning: Thank you for the reminder.
"You've jogged my memory."
Meaning: You jolted my memory and reminded me of something I had forgotten.
This is one of the closest English expressions to the proverb.
"I had forgotten all about it until you mentioned it."
Meaning: I had completely forgotten it until you mentioned it.
The closest equivalent in meaning to the proverb is:
“You’ve jogged my memory.”
“You have awakened my memory and reminded me of what I had forgotten.”
If the proverb's narrative meaning is emphasized—that the opponent reminded him of the weapon he possessed, which he then used against him—the closest English expression is:
“You reminded me of a weapon I had forgotten I possessed.”
“You reminded me of a weapon I had forgotten I possessed.”
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قيل‏:‏ إن أصله أن رجلا حَمَلَ على رجل ليقتله، وكان في يد المحمول عليه رُمْح فأنساه الدهش والجزَعُ ما في يده، فقال له الحامل‏:‏ ألْقِ الرمْحَ، فقال الآخر‏:‏ إنَّ معي رمحا لا أشعر به‏؟‏ ذكَّرْتَنِي الطَّعْنَ - المثلَ، وحمل على صاحبه فطعنه حتى قتله أو هَزَمه، يضرب في تذكر الشيء بغيره‏.‏
يقال‏:‏ إن الحامل صَخْر بن مَعَاوية السُّلَمي، والمحمول عليه يزين بن الصَّعِق‏.‏
وقال المفضل‏:‏ أول من قاله رهيم بن حزن الهلالي، وكان انتقل باهله وماله من بلده يريد بلدا آخر، فاعترضه قوم من بني تغلب فعرفوه وهو لا يعرفهم، فقالوا له‏:‏ خَلِّ ما معك وانجُ، قال لهم‏:‏ دونَكم المال ‏ ولا تعرضوا للحُرَم، فقال له بعضهم‏:‏ إن أردْتَ أن نفعل ذلك فألقِ رمحك، فقال‏:‏ وإنَّ معي لَرُمْحاً‏؟‏ فشدَّ عليهم فجعل يقتلهم واحداً بعد واحد وهو يرتجز ويقول‏:‏
رُدُّوا علي أقْرَبِهَا الأقاصِيَا * إنَّ لها بِالْمَشْرَفِّي حَادِياَ
ذكَّرْتَنِي الطَّعْنَ وَكُنْتُ نَاسِيَا