Imam al-Shafi'i (may Allah have mercy on him) said: "Allah, exalted be His praise, said in what He urged the people of His religion to: 'And prepare against them whatever you are able of strength and of tethered horses, by which you may terrify the enemy of Allah and your enemy.' [Surah al-Anfal: 60]
The scholars of tafsir say that strength (in this verse) means archery."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / Q19727