וִיהִי־מָ֣ה אָר֔וּץ וַיֹּ֥אמֶר ל֖וֹ ר֑וּץ וַיָּ֤רָץ אֲחִימַ֙עַץ֙ דֶּ֣רֶךְ הַכִּכָּ֔ר וַֽיַּעֲבֹ֖ר אֶת־הַכּוּשִֽׁי׃
’But come what may, [said he,] I will run.’ And he said unto him: ‘Run.’ Then Ahimaaz ran by the way of the Plain, and overran the Cushite.
Read midrashic interpretation of II Samuel 18:23: and classical rabbinic exegesis.