distance tests a horse's stamina (/strength) —judge people after a period of time
? 我們是～。要做工作可以，以后有的是！ (馮志《敵后武工隊》 381) We like to judge people after a period of time. If you want to work for us,there is plenty to do!
路遙知馬力
distance tests a horse’s stamina
～，日久見人心。Distance tests a horse’s strength,and time proves a man’s loyalty.or:The strength of a horse is tested by the length of the journey,and a man’s heart is seen with the passage of time./～，事久見人心。As a long road tests a horse’s strength,so a long task proves a person’s heart.