Tosefta for Shabbat 121:4
ודילמא כחייא בר רב ס"ל והכי קאמר עשית של שמאל מכה
[No]. Perhaps he agrees with Hiyya b. Rab, and he meant thus: You treat the left [foot] as through it had a wound? Now, R. Johanan [here] follows his general view. For R. Johanan said: Like tefillin, so are shoes: just as tefillin [are donned] on the left [hand], so are shoes [put on] the left [foot first]. An objection is raised: When one puts on his shoes, he must put on the right first and then the left? — Said R. Joseph: Now that it was taught thus, while R. Johanan said the reverse, he who acts in either way acts [well].<span class="x" onmousemove="('comment',' [It is left to each individual to decide for himself whether to assign pride of place to the right or left side each enjoys in some respects distinction over the other. V. Tosaf.]. ');"><sup>4</sup></span>