Jesus used a lot of figurative language in his talk with the disciples, especially with various analogies and the vine metaphor. Eventually, Jesus would talk in plain speech about the Father. Jesus told the disciples that on that day the disciples "will ask in [Jesus's] name" (16:26). Based on the similar sentence structure to the commands from Matthew 5, it's likely that Jesus was making a call to the disciples to ask in Jesus's name to the Father (cohortative indicative used).
Additionally, Jesus talks about how he doesn't say that he would pray for the Father for the disciples because the Father loves the disciples and the disciples believed that Jesus is of God (16:26-27). The Father already cares for the disciples, so Jesus knew there is little need to pray to request care for the disciples (because he already does so).
Once again, Jesus reiterated that he "came forth from the Father and have come into the world" and that Jesus would later "leave the world and go to the Father" (16:28). We've seen Jesus talk about his link to the Father multiple times throughout John. The link is part of the reason why the disciples (even today's disciples in the present day) can approach the Father in Jesus's name.