The Jesus who instructs at minimum to invest with usury obviously isn't the same Jesus who instructs to lend expecting nothing in return

The idea that Jesus would countenance usury at all is preposterous, whether as a law-loving Jew or as an eschatological prophet of impending final judgment.

The sayings of Matthew 25 and Luke 19, the Parable of the Ten Talents, blessing usury clearly stem from the period of later church reflection on the delay of the parousia. They stress being adequately prepared for the future coming, which has been unaccountably delayed. Time is dragging on interminably. The sayings fail miserably even to imagine how such preparation is in conflict with the law. They give no thought to it. They cannot be "historical".

The same is true of Matthew 5 and Luke 6, though to a lesser extent. The sayings of the Sermon on the Mount have been colored by the delay, too, but are closer in spirit to the thought of the historical Jesus, for whom giving instruction about lending at all would have made no sense but who might have countenanced such a discussion because it was a burning topic in the law and the prophets. Lending at interest of any kind to a "brother" was simply forbidden, though obviously much abused.

Like the Sermon generally, instruction about lending is instruction about and for an interim which Jesus never imagined would come. What we observe here is community reflection, by a community which has already stopped liquidating all possessions in obedience to the call to discipleship and which still has worldly goods to lend. The community is reflecting on what Jesus might have said on the subject, given his high view of the law. Clearly the solution given in Matthew 5 and especially in Luke 6 to lend expecting no return, not even of the principal, is in conflict with the Parable of the Ten Talents (again, Luke has the keener take on Jesus' eschatology and its implications). But the solution does reflect the spirit of the call to discipleship, if not the practice: Sell that thou hast, give to the poor, come follow me. To this extent it is closer to the historical Jesus.

It is remarkable how incoherent is the tradition and its redaction on this point.

 

Thou oughtest therefore to have put my money to the exchangers, and then at my coming I should have received mine own with usury ... from him that hath not shall be taken away even that which he hath.

-- Matthew 25:27,29

Wherefore then gavest not thou my money into the bank, that at my coming I might have required mine own with usury? ... from him that hath not, even that he hath shall be taken away from him.  

-- Luke 19:23,26

Give to him that asketh thee, and from him that would borrow of thee turn not thou away. 

-- Matthew 5:42

Give to every man that asketh of thee; and of him that taketh away thy goods ask them not again. ... But love ye your enemies, and do good, and lend, hoping for nothing again; and your reward shall be great, and ye shall be the children of the Highest: for he is kind unto the unthankful and to the evil.

-- Luke 6:30,35

If thou lend money to any of my people that is poor by thee, thou shalt not be to him as an usurer, neither shalt thou lay upon him usury.

-- Exodus 22:25

And if thy brother be waxen poor, and fallen in decay with thee; then thou shalt relieve him: yea, though he be a stranger, or a sojourner; that he may live with thee. Take thou no usury of him, or increase: but fear thy God; that thy brother may live with thee. Thou shalt not give him thy money upon usury, nor lend him thy victuals for increase. 

-- Leviticus 25:35ff. 

Thou shalt not lend upon usury to thy brother; usury of money, usury of victuals, usury of any thing that is lent upon usury: Unto a stranger thou mayest lend upon usury; but unto thy brother thou shalt not lend upon usury: that the LORD thy God may bless thee in all that thou settest thine hand to in the land whither thou goest to possess it.

-- Deuteronomy 23:19f.

LORD, who shall abide in thy tabernacle? who shall dwell in thy holy hill? ... He that putteth not out his money to usury, nor taketh reward against the innocent.

-- Psalm 15:1, 5

He that hath not given forth upon usury, neither hath taken any increase, that hath withdrawn his hand from iniquity, hath executed true judgment between man and man, Hath walked in my statutes, and hath kept my judgments, to deal truly; he is just, he shall surely live, saith the Lord GOD.

-- Ezekiel 18:8f.

So likewise, whosoever he be of you that forsaketh not all that he hath, he cannot be my disciple.

-- Luke 14:33