const Command = require('../structures/command.js');

module.exports = class Ping extends Command {

  constructor(client) {
    super(client);

    this.name = "ping";
  }

  run(message) {
    var embed = this.client.getDekuEmbed(message).setDescription(':ping_pong: `...`');
    var startTime = Date.now();
    message.channel.send({embed}).then((message) => {
        var endTime = Date.now();
        embed.setDescription(`:ping_pong: \`${Math.round(endTime - startTime)}ms\``)
        message.edit({embed});
    });
  }

}

@@ -343,17 +343,20 @@
 ).then((
-m
+newM
 essage) 
@@ -444,38 +444,45 @@
 %5C%60$%7B
-Math.round(endTime - startTime
+(newMsg.createdAt - message.createdAt
 )%7Dms

Change what @davipatury requested