CHASE

Portamento is clearly envisaged here.

David keeps this and the following bar on the D string, enabling two expressive portamentos.

Here (and 4 bars later) David will undoubtedly have allowed the open D-string to sound between the 1st and 2nd notes.

Here (and 4 bars later) it is likely that David will have placed the 1st finger on e' or the 3rd across 2 strings so that the string crossing can be achieved without breaking the legato or introducing a dissonant note into the harmony.