This is proof enough that the soul does not refer to any spiritual element within man; here, 'soul' (Greek 'psuche') just means one's physical life, which is how it is translated here.
Huu ni ushahidi wa kutosha wa nafsi hakitajwi kitu chochote cha kiroho ndani ya mtu; hapa,'nafsi’ (Kiyunani'psuche’) ina maana uhai wa mwili wa mtu tu, ndivyo lilivyotafsiriwa hapa